The 1973 Design Guide required a minimum private (i.e. rear) garden size of 100m² for most types of houses. This provision has been found to be an acceptable and workable minimum size that accommodates most household activities and is at the same time adequate to offer visual delight, receive some sunshine, and encourage plant growth. Storage sheds and space for drying areas and wheeled bins are often required. Allowance should be made within the scheme design. The BRE report "Site Layout Planning for Daylight and Sunlight" recommends that certainly no more than two fifths and preferably no more than a quarter of the garden should be prevented by buildings, walls or fences from receiving sunshine on 21 March. 

The 100m² minimum garden size is easily achievable for three or more bedroom houses provided the houses are of wide frontage format, but narrow fronted houses may result in longer, narrower gardens. Given the constraints of rear access this can be a reason for minimising the use of this type of house.

Generally, designers should try to create as far as possible usable rectangular garden shapes. Some local authorities may have different minimum garden sizes, and applicants should consult the relevant District Council Planning Department.

There are circumstances under which the insistence on a minimum 100m² garden size is  not appropriate. These are as follows:

Houses of One or Two Bedroom Size

Such houses usually have such a small footprint that provision of a 100m² garden is not practicable without being excessively long and thin. In any case, since these are dwellings for smaller households the requirement by residents for garden area is less. Different local planning authorities have varying garden size standards for one and two-bedroom houses. 50m² is the most common, but applicants should consult the relevant District Council Planning Department. 

These houses must be indicated as being either extendable or unextendable. In the case of an extendable house, the initial planning application must show the shape of an eventual extension, and the garden area must be calculated excluding the ground that would be occupied by the eventual extension. Unextendable  houses will have the householder's right to extend under the General Permitted Development Order withdrawn. Permitted Development (PD) rights to extend will also be withdrawn where the garden is less than 50m². In the case of unextendable houses some local planning authorities may allow communal garden provision. In such cases this will be to the standard for flats, i.e. 25m² per dwelling minimum, and a planning condition will be imposed that the garden is to remain communal in perpetuity. 

This garden space is to be entirely on the private, non-entrance side of  the house and to contain a screened, un-overlooked sitting-out area adjacent to each house. Again, applicants should consult their local planning authority to see whether they accept communal garden provision in such situations. 

Walled Patios or Private Courtyards

In higher density situations it may be appropriate to reduce minimum garden sizes provided a private, sitting-out area for each house can be achieved, un-overlooked by any window either at ground or first-floor. The loss of sunlight in such situations may be an acceptable price to pay for a tighter urban format or closer proximity to central facilities for example. PD rights to extend will be withdrawn in these cases.

Houses facing, backing on to, or adjacent to a substantial area of well landscaped and properly maintained communal open space

This is the situation analogous to the Georgian square, in which residents have immediate access to the communal space for children's play and sitting-out. In such cases a private garden may not be required, though different planning authorities will have varying policies. Again PD rights to extend will be withdrawn.

Houses Performing a Particular Role in the Layout

Where the majority of houses comply either with the 100m² minimum garden size or one of the other standards above there may be some houses which, due to their situation in the layout, cannot be provided with a private garden to the required standard.

These may be, for example, houses which turn external corners or are required for townscape reasons in locations which are hemmed in at the rear. If the standard were strictly adhered to there would be gaps in these positions, and the whole street scene would be the poorer for their lack. In a development comprising a number of houses, purchasers will have the choice whether or not to buy one of these 'special' houses, and planning authorities should therefore be flexible as to how much private garden area they will require in such situations.

Flats

For two or more bedroomed flats communal residents' gardens must be provided on the basis of a minimum area of 25m² per flat. They must be screened by above-eye-level walls or hedges, and must contain a sitting-out-area that receives sunshine during at least part of the day. Unusable strips of space between car parks or roads and buildings will not be counted as part of the communal garden provision. Although similar provision is welcomed for one-bedroomed flats it is recognised that residents of such flats may be happy to forego this amenity if there is access to other local open space, and in order to have the benefits of living in a town centre  or other core area. Applicants should check with their local planning authority the circumstances under which a garden for one-bedroomed flats may be foregone. 

In addition balconies may provide outdoor amenity space in closer proximity to an upper storey dwelling. A balcony or terrace over 5m² in extent will count towards the total garden provision for the flats. In an urban situation on sites of less than 0.1h such a balcony or terrace would be acceptable as the only outdoor amenity space for a flat. Care must be taken to limit overlooking of nearby private gardens and sitting out areas from balconies or terraces. It may be necessary to provide other space around the development additional to this minimum requirement in the case of flats located in a Boulevard planned area.